"""
if的多分支:
语法:
if 条件1:
    代码块1
elif 条件2:
    代码块2
elif 条件3:
    代码块3
......
else:
   代码块n
"""
# rizi=input("请输入日子:")
# if rizi == "情人节":
#     print("买花")
# elif rizi=="平安夜":
#     print("吃大餐")
# elif rizi=="生日":
#     print("买蛋糕")
# else:
#     print("上班")
age=int(input("请输入年龄:"))
# if age<10:
#     print("小孩")
# elif 10 <= age <= 20:
#     print("小朋友")
# elif  age >20 and age<=30:
#     print("年轻人")
# elif  age >30 and age<=50:
#     print("中年人")
# else:
#     print("老年人")
#
if age>50:
    print("老年人")
elif age >30:
    print("中年人")
elif age >20:
    print("年轻人")
elif age >10:
    print("小朋友")
elif age>0:
    print("小孩")
# else:
#     print("输入有误")
if age<0:
    print("输入有误")



# if age>50:
#     print("老年人")
# if age >30:
#     print("中年人")
# if age >20:
#     print("年轻人")
# if age >10:
#     print("小朋友")
# else:
#     print("小孩")